Buggy code:
public static final int METHOD_REF = 68 ; public static final int METHOD_REF_PARAMETER = 69 ; public static final int ENHANCED_FOR_STATEMENT = 70 ; public static final int ENUM_DECLARATION = 71 ; public static final int ENUM_CONSTANT_DECLARATION = 72 ; public static final int TYPE_PARAMETER = 73 ; public static final int PARAMETERIZED_TYPE = 74 ; public static final int QUALIFIED_TYPE = 75 ; public static final int WILDCARD_TYPE = 76 ; public static final int NORMAL_ANNOTATION = 77 ; public static final int MARKER_ANNOTATION = 78 ; public static final int SINGLE_MEMBER_ANNOTATION = 79 ; public static final int MEMBER_VALUE_PAIR = 80 ; public static final int ANNOTATION_TYPE_DECLARATION = 81 ; public static final int ANNOTATION_TYPE_MEMBER_DECLARATION = 82 ; public static final int MODIFIER = 83 ; public static Class nodeClassForType ( int nodeType ) { } final AST ast ; private ASTNode parent = null ; private static Map UNMODIFIABLE_EMPTY_MAP = Collections . unmodifiableMap ( new HashMap ( 1 ) ) ; private Object property1 = null ; private Object property2 = null ; private int startPosition = - 1 ; private int length = 0 ; public static final int MALFORMED = 1 ; public static final int ORIGINAL = 2 ; public static final int PROTECT = 4 ; int flags = 0 ; private StructuralPropertyDescriptor location = null ; static boolean CYCLE_RISK = true ; static boolean NO_CYCLE_RISK = false ; static boolean MANDATORY = true ; static boolean OPTIONAL = false ; class NodeList extends AbstractList { ArrayList store = new ArrayList ( 0 ) ; ChildListPropertyDescriptor propertyDescriptor ; class Cursor implements Iterator { private int position = 0 ; public boolean hasNext ( ) { } public Object next ( ) { } public void remove ( ) { } void update ( int index , int delta ) { } } private List cursors = null ; NodeList ( ChildListPropertyDescriptor property ) { } public int size ( ) { } public Object get ( int index ) { } public Object set ( int index , Object element ) { } public void add ( int index , Object element ) { } public Object remove ( int index ) { } ASTNode . NodeList . Cursor newCursor ( ) { } void releaseCursor ( ASTNode . NodeList . Cursor cursor ) { } private void updateCursors ( int index , int delta ) { } int memSize ( ) { } int listSize ( ) { } } ASTNode ( AST ast ) { } public final AST getAST ( ) { } public final ASTNode getParent ( ) { } public final StructuralPropertyDescriptor getLocationInParent ( ) { } public final ASTNode getRoot ( ) { } public final Object getStructuralProperty ( StructuralPropertyDescriptor property ) { } public final void setStructuralProperty ( StructuralPropertyDescriptor property , Object value ) { } int internalGetSetIntProperty ( SimplePropertyDescriptor property , boolean get , int value ) { } boolean internalGetSetBooleanProperty ( SimplePropertyDescriptor property , boolean get , boolean value ) { } Object internalGetSetObjectProperty ( SimplePropertyDescriptor property , boolean get , Object value ) { } ASTNode internalGetSetChildProperty ( ChildPropertyDescriptor property , boolean get , ASTNode child ) { } List internalGetChildListProperty ( ChildListPropertyDescriptor property ) { } public final List structuralPropertiesForType ( ) { } abstract List internalStructuralPropertiesForType ( int apiLevel ) { } static List tempPDL = null ; static void createPropertyList ( Class nodeClass ) { } static void addProperty ( StructuralPropertyDescriptor property ) { } static List reapPropertyList ( ) { } final void unsupportedIn2 ( ) { } final void supportedOnlyIn2 ( ) { if ( ( this . ast . apiLevel ) != ( LEVEL_2_0 ) ) { <START_BUG> throw new UnsupportedOperationException ( "Operation<seq2seq4repair_space>not<seq2seq4repair_space>supported<seq2seq4repair_space>in<seq2seq4repair_space>2.0<seq2seq4repair_space>AST" ) ; <END_BUG> } } final void setParent ( ASTNode parent , StructuralPropertyDescriptor property ) { } public final void delete ( ) { } static void checkNewChild ( ASTNode node , ASTNode newChild , boolean cycleCheck , Class nodeType ) { } final void preReplaceChild ( ASTNode oldChild , ASTNode newChild , ChildPropertyDescriptor property ) { } final void postReplaceChild ( ASTNode oldChild , ASTNode newChild , ChildPropertyDescriptor property ) { } final void preValueChange ( SimplePropertyDescriptor property ) { } final void postValueChange ( SimplePropertyDescriptor property ) { } final void checkModifiable ( ) { } final void preLazyInit ( ) { } final void postLazyInit ( ASTNode newChild , ChildPropertyDescriptor property ) { } public final Object getProperty ( String propertyName ) { } public final void setProperty ( String propertyName , Object data ) { } public final Map properties ( ) { } public final int getFlags ( ) { } public final void setFlags ( int flags ) { } public abstract int getNodeType ( ) { } public final boolean equals ( Object obj ) { } public abstract boolean subtreeMatch ( ASTMatcher matcher , Object other ) { } public static ASTNode copySubtree ( AST target , ASTNode node ) { } public static List copySubtrees ( AST target , List nodes ) { } final ASTNode clone ( AST target ) { } abstract ASTNode clone0 ( AST target ) { } public final void accept ( ASTVisitor visitor ) { } abstract void accept0 ( ASTVisitor visitor ) { } final void acceptChild ( ASTVisitor visitor , ASTNode child ) { } final void acceptChildren ( ASTVisitor visitor , ASTNode . NodeList children ) { } public final int getStartPosition ( ) { } public final int getLength ( ) { } public final void setSourceRange ( int startPosition , int length ) { } public final String toString ( ) { } final String standardToString ( ) { } void appendDebugString ( StringBuffer buffer ) { } final void appendPrintString ( StringBuffer buffer ) { } static final int HEADERS = 12 ; static final int BASE_NODE_SIZE = ( ASTNode . HEADERS ) + ( 7 * 4 ) ;

Fix:
throw new UnsupportedOperationException ( "Operation<seq2seq4repair_space>only<seq2seq4repair_space>supported<seq2seq4repair_space>in<seq2seq4repair_space>2.0<seq2seq4repair_space>AST" ) ;